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<TITLE>Magic-7.3 Command Reference</TITLE>
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<H2>undo</H2>
<HR>
Undo commands
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<H3>Shortcuts:</H3>
   <BLOCKQUOTE>
      Key macro <B>U</B> implements the command <B>undo</B>.
   </BLOCKQUOTE>

<H3>Usage:</H3>
   <BLOCKQUOTE>
      <B>undo</B> [<B>print</B> [<I>count</I>]] <BR><BR>
      <BLOCKQUOTE>
         where <I>count</I> indicates a number of events to be undone
	 (default 1 event), and must be a nonzero positive integer.
      </BLOCKQUOTE>
   </BLOCKQUOTE>

<H3>Summary:</H3>
   <BLOCKQUOTE>
      The <B>undo</B> command reverses the effect of the last
      executed command (command-line, script, or macro-invoked),
      returning the layout to the state it was in prior to
      execution of that command. <P>

      Certain commands in <B>magic</B> disable the undo mechanism,
      thus preventing the command from being undone.  These include
      layout reads and writes, CIF, GDS, and LEF/DEF reads and
      writes.

      The <B>print</B> option generates a stack trace of the top
      <I>count</I> events in the undo stack, in excruciating
      detail.
   </BLOCKQUOTE>

<H3>Implementation Notes:</H3>
   <BLOCKQUOTE>
      <B>undo</B> is implemented as a built-in window command in <B>magic</B>.
   </BLOCKQUOTE>

<H3>See Also:</H3>
   <BLOCKQUOTE>
      <A HREF=redo.html><B>redo</B></A> <BR>
   </BLOCKQUOTE>

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<P><I>Last updated:</I> October 15, 2004 at 5:55am <P>
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